This is a Phase I proposal todemonstrate the value and practicality of developing atwo volume textbook/training manual for: a) the design, conduct and analysis of clinical trials; and b) the design, conduct and analysis of case-controlled studies. Tothis end, modules will be developed which integrate text, statistical software and illustrative datasets to provide a packagefor self-instruction or use in a training course. Software will be based on existing commercial software packages, EPILOG PLUS and POWER, developed bya consultant to this project. Datasets will be derived from NIH-funded clinical trials and case- control studies to illustrate the procedures being taught.